Multiple push rod switch with interlatch and lockout means



Dec. 30, 1969 G. M. STOUT 3,487,178

MULTIPLE PUSH ROD SWITCH WITH INTERLATCH AND LOCKOUT MEANS Filed Aug. 17, 1967 2 Sheets-Sheet 1 M9 i ZZFWF INVENTOR L /v/v M. STOUT BYMfi/UJMM ATT'YS.

Dec. 30, 1969 G. M. STOUT 3,487,178

MULTIPLE PUSH ROD SWITCH WITH INTERLATCH AND LOCKOUT MEANS Filed Aug. 17, 1967 2 Sheets-Sheet 2 INVENTOR GLENN M. STOUT wmzw v :A TfYs.

United States Patent 3,487,178 MULTIPLE PUSH ROD fi'WITCH WITH INTER- LATCH AND LOUKOUT MEANS Glenn M. Stout, Minneapolis, Minn., assignor to Seven US, Inc., Minneapolis, Minn, a corporationof Illinois Filed Aug. 17, 1967, Scr. No. 661,378 Int. Cl. H0111] 9/26 U.S. Cl. 200- 11 Claims ABSTRACT OF THE DISCLOSURE A multi-station switch assembly for controlling a plurality of circuits which is characterized by a number of plungers slidable in guides between a pair of spaced frame plates and each carrying an actuator for an associated leaf spring contact switch mounted in the path thereof and a series of lockout members disposed in a guideway between the plates for operation by the ends of the plungers to lock the remainder of the plungers against operation when one of the plungers is depressed and also to control an actuator for a key motion sensing switch mounted at the end of the frame plates. The assembly includes a slidably mounted spring-held latch bar associated with the plungers and automatically moved to release position by cam surfaces on the plungers so that depressing one plunger automatically releases a previously depressed plunger for return to raised or non-actuating position by a return spring associated therewith.

This invention relates to electrical switch assemblies and is more particularly concerned with improvements in a multi-station switch having interlatched stations and a lockout mechanism.

Multiple station switch assemblies have heretofore been developed for use where it is desired to provide selective control over a number of operations or control in a continuous sequence of operations. Such switches are increasingly used in home appliances such as electric ranges, washing machines, air conditioners and like equip ment. Also there is increasing demand for push-button or push rod gang switches in more complex electric equipment such as communication and instrument gear, computer and oflice equipment devices and other mechanical equipment employing multiple circuits for the control thereof. In this type switch equipment it is, of course, desirable to provide smooth operating eificient devices which are of simplified structure, easy to maintain in working condition, readily manufacturable and low in cost. Also because of the restricted space in which such devices are frequently mounted, it is desirable that they be easily installed, removed or replaced, easy to wire and that they should have a high degree of functional flexibility and versatility. It is, therefore, an object of the present invention to provide an improved switch assembly of the multiple push button type which is of relatively simple construction, which will operate efiiciently and smoothly over a long period with minimum attention, which may be readily manufactured at a relatively low cost and which has other desirable characteristics and advantages.

A more specific object of the invention is to provide an improved multi-station switch which includes a plurality of reciprocably mounted switch actuating push rod members and associated guide members which insure smooth operation of the actuating members and an interlatch arrangement so that when one of the actuating members is depressed a previously depressed actuating member will be automatically released for return to non-actuating position.

Another object of the invention is to provide an im- 3,487,178 Patented Dec. 30, 1969 proved multiple push button switch wherein a plurality of switch actuating members are mounted for reciprocation between spaced frame plates and guided by means of plastic inserts which are readily assembled with the frame plates so as to facilitate initial assembly and installation and replacement when required and which insure smooth operation of the actuating members.

A further object of the invention is to provide in a gang switch having a plurality of push rod type switch actuating members, a common latch bar with spaced detents thereon for cooperation with carnming and latching surfaces on the actuating members so as to lock the individual push rod members in switch actuating position when they are depressed and to automatically release a previously latched member prior to latching the member which is being depressed.

Another object of the invention is to provide in a multiple push rod switch, a latch bar having a series of detents spaced along the same for cooperation with cam and latch details on the push rods, thereby enabling ready variation of operations in a single bank switch by the substitution of diiferent push rod structures without modification of the latch bar.

A still further object of the invention is to provide in a multiple push button switch a contact actuator formed of a rigid plastic material with external ribs for engaging leaf spring contacts which actuator is carried on the push button plungers so as to engage the contacts without abrupt angle changes thereby insuring smooth operation and with the contacts having smooth surface portions intermediate the side edges thereof riding on the ribs so as to be held clear of the adjacent actuator surfaces thereby avoiding undesirable engagement of the edges of the contacts with the latter.

Another object of the invention is to provide a multiple push button switch having a plurality of switch actuating plunger members and lockout slugs cooperating therewith to insure that only one plunger at a time is in depressed position and a switch actuator which is operable through movement of the lockout slugs for controlling a key motion sensing switch mounted at the end of the switch bank.

A further object of the invention is to provide a multiple push rod switch assembly having interlatch and lockout features wherein the lookout feature comprises individual lockout slugs for each push rod which may be readily removed or replaced with modified forms thereof to convert the assembly to other operations.

These and other objects and advantages of the invention will be apparent from a consideration of the push button switch structure which is shown by way of illustration in the accompanying drawings wherein:

FIGURE 1 is a side elevation of a multiple push button switch assembly having interlatch and lockout features which embodies the principles of the invention;

FIGURE 2 is an end view of a switch assembly of FIGURE 1 to an enlarged scale;

FIGURE 3 is a partial section taken on the line 33 of FIGURE 2 with one of the push buttons latched in depressed position;

FIGURE 4 is a cross-section taken on the line 44 of FIGURE 1 to an enlarged scale;

FIGURE 5 is an exploded perspective view showing the cements at one of the switch assembly; and

FIGURE 6 is an exploded end view illustrating the assembly of the plunger and associated elements with the main support plate.

The switch assembly which is illustrated in the drawings is designed to enable one of a plurality of push button rods or plungers to be depressed from a normal inoperative position to an operative switch actuaing position and at the same time automatically to release or restore to inoperative position an associated plunger which has been previously depressed and latched in switch activating position. In addition there is incorporated in the assembly lockout mechanism and a key motion switch actuator which is operated upon depressing any of the plungers. With slight modification the switch assembly may be converted to provide non-locking plunger action or other arrangements by omission or modification of the lockout mechanism and/or the substitution of plungers of different construction.

Referring to the drawings there is illustrated a push button switch assembly having nine switch stations. However, it is understood that the number of stations can be decreased or increased. The assembly comprises two frame plates 14) and which are of substantially identical construction except for being rights and lefts. The plates 10 and 10' are of suitable rigid material such as sheet steel and may be stamped or otherwise formed in any desired lengths. The plates include rectangular body portions with bottom edges 12, 12', end edges 13, 13' and 14, 14' and top flanges 15, 15'. When the plates are assembled to form a supporting frame for the switch elements, they are positioned in face to face relation with the flanges 15, 15' extending in opposite directions. The flanges 15, 15' may have any desired width and may be provided with suitable apertures for mounting the entire structure in a panel or the like. The body of each of the plates 10 and 10' is provided with a series of closely spaced generally rectangular apertures 16 and 16 and the apertures 16 are aligned in paired relation with the apertures 16' when the plates are assembled so as to form guideways for receiving contact actuators 18 and plunger guides 20 associated with plunger or push rod members 22. When assembled the plates 10 and 10 are held in spaced relation at the bottom by a spacer bar 23 and at the top by small spacer sleeves 24 carried on spaced clamping bolts 25 which are disposed along the top margin of the body of the plate 10, the latter constituting in effect the main support plate. The spacing between the plate bodies is slightly greater than the thickness of the plunger member 22 so as to permit free sliding movement of the plunger members 22 in a vertical direction when the frame is disposed with the flanges 15, 15 generally horizontal. The frame spacer 23 is apertured to accommodate a series of spaced clamping bolts 26 on which leaf spring contact switch point assemblies 28 are mounted on the outside face of the body portion of the frame late 10'. Each leaf spring assembly 28 comprises a plurality of sets of stacked contact blades 30 seated in pockets 31 which are formed on an elongate insulating bar 32 by longitudinally spaced partition members 33 with the spaces forming the pockets 31 having a width determined according to the spacing of the bolts 26 each of which is located below a lower corner of an aperture 16 so that when the contact switch assemby 28 is positioned in a pocket 31 the switch blades 30 extend upwardly along the one side of an aperture 16 with the innermost blade 34 positioned for engagement by the contact actuator 18 which is carried on the plunger 22. The insulating bar 32 and associated partition members 33 may be formed of a suitable rigid plastic having electrical insulating characteristics.

The interlatch plunger 22 is in the form of a flat plate of rigid material, such as, for example, metal cut from a rectangular strip, so as to provide a relatively wide top portion 35 and a narrower bayonet-like or spear-like bottom portion 36. An elongated aperture 37 is provided in the top portion 35 near the bottom margin thereof and extending on the vertical axis for receiving the guide pin 38 which extends from the innermost face of the main support plate 10 and is centered at the top of the aperture 16. The top portion 35 of the interlatch plunger 22 is notched out at 39 along the one side edge to provide a relatively long clearance slot when positioned at an aperture 16 adjacent a separating collar 24. The opposite vertical margin of the plunger top portion 35 is notched at 40 to provide a latching slot and at 41 to provide an outwardly and upwardly inclined cam edge 42 for latch bar operation as hereinafter described. The top portion 35 of the plunger 22 is provided with an operating button 43 on the top surface of which identifying indicia may be placed. The bottom spear-like portion 36 of the plunger 22 has tapered edges 44- which converge to a somewhat rounded point for co-operation with a lockout mechanism which will be described.

A plunger guide 20 is associated with each of the plungers 22 and is in the form of a generally rectangular block of a suitable molded plastic having the necessary dimensional stability. It is provided with a fiat top surface 45 and the end portions are bifurcated or slotted at 46 and 46, the widths of the slots being slightly greater than the thickness of the material in the plate 10 and the distance between the base of the slots being slightly less than the width of the aperture 16. The center portion of the guide 20 is thickened as indicated at 50 and when the guide 20 is installed in the frame plate 10, this thickened center portion is seated in a notched-out portion 51 in the bottom edge of the aperture 16 which is of complementary shape. The guide 20 is adapted for assembly with the base forming main frame plate 10 by positioning the same diagonally in an aperture 16 and engaging opposite edges defining the aperture 16 in the slots 46 and 46 at the ends of the guide. A vertically disposed aperture 52 is provided in the center of the guide 20' which is adapted to receive in free sliding relation the bottom portion 36 of the plunger 22. The relative dimensions of the aperture 52 and the plunger portion 36 are such that the plunger portion 36 may be canted therein slightly during assembly and disassembly of the plunger with the plate 10 as illustrated in FIGURE 6 so as to free slot 37 of the pin 38 and permit the plunger 22 and the associated actuator 18 to be maneuvered into or out of proper assembled relation with the base plate 10.

The contact actuator 18 is in the form of a block which is preferably molded from a rigid plastic material which has dimensional stability. It has a vertical dimension which is substantially less than the corresponding dimension of the aperture 16 so that it may have a predetermined path of vertical movement when installed in the aperture 16. The over-all length of the actuator 18 is greater than the width of the aperture 16 in the plate 10 and the end portions are reduced in width or thickness so as to provide flange-like extensions 53 and 53' for positioning between marginal plate portions defining the vertical slides of the apertures 16 and 16' in the plates 10 and 10', with the latter forming tracks for guiding the actuator 18 in its vertical movement. A vertically disposed slot 54 of rectangular cross-section extends through the actuator 18 and receives in sliding relation the bottom portion 36 of the plunger 22. The slot 54 which is aligned with the space between the plates and centered so as to receive the plunger portion 36, has a widened portion 54 at the top in which the bottom edge of the plunger top portion 35 is adapted to seat. The bottom face of the actuator 18 is plain and is adapted to abut the top face 45 of the plunger guide 20 when the plunger 22 is depressed to its lowermost position. A return spring 55 has its uppermost end seated in a pocket 56 (FIGURE 4) provided in the bottom face of the actuator 18. The spring 55 is carried on the plunger portion 36 and serves to urge the actuator 18 in the direction of its uppermost position. The actuator 18 is widened at the top margin so as to provide outwardly and upwardly inclined surfaces 57 and 57 along the top margins and spaced rib formations 58 are provided on opposite faces which project outwardly of the surface and which extend near the vertical edges in a position to be engaged by the innermost face of the innermost leaf spring 34 in the stack 30 of each spring contact switch assembly 28. The top face of each actuator 18 is cut away to provide a relatively shallow recess or lengthwise extending slot 60' which is of a width sufiicient to seat therein the marginal portions of the frame plates and 10' at the top of the slots 16 and 16 when the actuator 18 is in its uppermost position.

A latch bar 61 having a series of longitudinally spaced elongated apertures 62 is mounted in sliding relation on the bolts 25 on the outside face of the frame plate 10'. The apertures 62 are spaced so as to permit limited sliding movement on spacer members 63 on the bolts 25. Latch pins 64 (FIGURE 3) extend from the latch bar 61 through apertures 65 provided in the main frame plate 10 and engage in the notches 41 in the plungers 22 when the latch bar 61 is in its normal operative position and the plungers 22 are at the uppermost end of their path. The latch bar 61 is held in the position shown in FIGURE 1 by a return spring 66 (FIGURE 1) attached at one end to a pin 67 on the latch bar and at the other latch bar in operative position. When a plunger 22 is initially depressed the inclined surface 42 at the top of the notch 41 engages the latch bar pin 64 and moves the latch bar 61 to inoperative or non-latching position, relative to all of the plungers 22, against the tension of the return spring 66. When a plunger 22 is fully depressed as shown in FIGURE 3 the latching notch 40 is positioned to receive the latch bar pin 64 which permits the latch bar 61 to be returned to latching position by the return spring 66. The movement of the latch bar to non-latching position by engagement of a pin 64 by the cam edge 42 of any one of the plungers 22 automatically releases any previously engaged or latch plunger 22 which is returned to its raised position by the associated return spring 55 so that any previously latched plunger 22 which has been depressed is automatically released by initial depression of any other plunger 22.

The base or main plate 10 is provided along its lower margin with a series of equally spaced buttons or protrusions 70 which extend inwardly of the innermost face thereof and which are centered between the apertures 16 in the base plate 10. These stop buttons 70 cooperate with lockout slugs 71 which are formed from generally rectangular strips of rigid metal plate material of a thickness somewhat less than the spacing between the frame plates 10 and 10' so as to be received in loosely sliding relation in the bottom of said space, as shown in FIG- URE 3, with the stop buttons 70 accommodated in a U-shaped slot or recess 72 in the top margin of each lockout slug 71. The lockout slugs 71 have a straight bottom edge 73 which rides on the top edge of the spacer bar 23 between the frame plates 10 and 10'. The end edges of each slug 71 are tapered or slanted inwardly in converging planes at '74 and 74' with the taper or inclination corresponding approximately to the taper 44 on the bottom end of the bottom portion 36 of the plungers 22. The lockout slugs 71 are positioned so that adjacent ends abut each other and the tapered surfaces are disposed below the plungers 22 so that when a plunger 22 is depressed fully the slugs immediately below the same are cammed apart and the line of slugs is moved so as to block depressing of all of the other plungers 22. In addition there is provided at the end of the frame plates 10 and 10' an actuator 75 for a key motion sensing switch 76 which is mounted at the end of the assembly. The actuator 75 is operated by movement of the line of lockout slugs 71 when any plunger 22 is depressed as illustrated in FIGURE 3. The actuator 75 is of plate-like form and of non-conductive material such as a rigid plastic. It has an open slot 77 cut in the top edge for accommodating the end stop button 70. The innermost edge of the actuator 75 has a tapered or inclined cam portion 78 for co-operation with the tapered edge 44 on the bottom end of portion 36 of the endmost plunger 22. The switch blade 80 of the switch 76 extends into the path of the end portion 81 of the actuator 75 and the contacts 82 are closed when any one of the plungers 22 is depressed. When the depressed plunger 22 is released for return to an inoperative position by actuation of the latch bar 61, the spring contact blade returns the actuator 75 to the non-actuating position where it remains until moved by the depression of a plunger 22.

In assembling the switch, no jigs or fixtures are required. The guide members 20 may be positioned in the apertures 16 in the main plate 10 with the plate edges disposed in the end slots 46 and 46' after which an actuator 18 and a spring 55 may be assembled on the end portion 36 of each plunger 22 and the latter inserted in the aperture 52, as indicated in FIGURE 6, so as to fully seat the actuator 18 in the aperture 16, (FIGURE 4), the plunger 22 being depressed and tilted into position so as to bring the guide pin 38 into the plunger slot 37. The lockout slugs 71 and switch actuator 75 may be positioned as shown in FIGURE 3 after which the assembly is completed by attaching the plate 10" with switch assemblies 28 and latch bar 61. The switch assemblies 28 may have a common bus bar 83 to facilitate wiring. The disassembly of the switch elements merely requires reversing the assembly operations which facilitates repair or modification of the unit after installation. Disassembly may be had without any flying apart of any of the switch elements.

The latch bar 61 may be released by incorporating a plunger member having a suitable cam edge for engaging a pin on the bar or it may be operated by an electromagnet or any other suitable means.

The lockout feature may be modified, for example, by providing a modified lockout slug of sufficient length and having a slot 72 of a length to span two or more of the stops 70 thereby blocking the depressing movement of one or more of the plunger end portions 36.

I claim:

1. A multiple station switch assembly comprising a pair of rigid plate members disposed in parallel spaced relation so as to form a housing and having aligned apertures in paired relation with the oppositely disposed edge portions forming parallel guideways therein, a plurality of switch means mounted on an outside face of said housing adjacent said apertures, a plurality of switch actuators. each mounted in reciprocal sliding relation and being guided by said pair of aligned apertures, push rods slidably connected to each of said actuators which are operaable for manually moving said actuators individually between switch actuating and nonactuating positions, a latch bar mounted on said housing and movable in a path which is normal to the path of movement of said push rods, said latch bar and said push rods having iuterengaging cam and latch means which cooperate in moving said latch bar between a position for latching said push rods when they are in switch actuating position and a position where said push rods are released for movement of said associated switch actuators to a non-actuating position and lockout means co-operating with said push rods which is operated upon movement of a push rod to a switch actuating position and blocks the movement of the remaining push rods to a switch actuating position.

2. A multiple station switch assembly as set out in claim 1 and the iuterengaging cam and latch means for moving said latch bar including pins on said latch bar and notches in the side edge of each push rod which are adapted to receive said pins with one of said notches having a cam forming edge for enaging a pin on said latch bar when said push rod is operated so as to shift the latch bar to non-latching position.

3. A multiple station switch assembly as set out in olaim 1 and guide inserts for each of said push rods seated in the apertures in said plate members in spaced relation to said switch actuators,

4. A multiple push button switch having a supporting frame member with spaced apertures therein, the oppositely disposed edges of which form guide tracks, switch actuators mounted on said guide tracks for movement between switch actuating and non-actuating positions, switch means mounted on said supporting frame and disposed in the path of said actuators for operation by the same, reciprocable plunger members slidably connected with said actuators and operable to move said actuators to switch actuating position, inserts forming guides for said plunger members mounted on said guide tracks in spaced relation to said switch actuators, resilient means urging said switch actuators toward a non-actuating position, and means for releasably latching each plunger when it is moved to switch actuating position.

5. A multiple push button switch as set forth in claim 4 and each said switch actuator and associated plunger guide having recesses which are aligned so as to receive portions of a plunger member in sliding relation.

6. A multiple push button switch as set forth in claim 4 and the switch actuators and plunger guides having recesses aligned to receive portions of the plunger members with the resilient means for urging the actuators toward a non-actuating position interposed between each actuator and an associated plunger guide.

7. A multiple push button switch as set forth in claim 4 and said supporting frame member having a guideway formation and U-shaped lockout members movable therein having cam surfaces for engagement therewith of a plunger member when the plunger member is moved toward switch actuating position so as to move the lockout members to block the movement of certain other plunger members.

8. In a switch assembly having a supporting frame member with spaced apertures having oppositely disposed edges which form tracks guiding switch actuators and associated operating plungers, a switch actuator supported by said tracks which is in the form of a generally rectangular block of insulating material with rib-like portions at oppositely disposed side edges engaging said tracks and of a size relative to the size of the apertures to permit movement of said actuator between a switch operating position and a non-operating position by reciprocation of the associated operating plunger and means whereby said switch actuator may be moved laterally of said frame member into seating engagement in the associated aperture.

9. In a switch assembly having a supporting frame member with spaced apertures, the oppositely disposed edge portions of which form tracks for reciprocably mounting a switch actuator carried on a plunger which actuator is mounted for reciprocable movement along the face of the frame member, a plunger guide insert seated in each of said apertures which is in the form of a generally rectangular block with opposite side edges having grooves encompassing the track forming edge portions of said supporting frame member and of a size relative to the size of the apertures with the guiding portion of said insert receiving an end portion of said plunger.

10. In a switch assembly as set forth in claim 9 and said plunger guide insert having an aperture extending in the direction of movement of the plunger so as to slidingly receive in guiding relation the end of the plunger.

11. A multiple push button switch having a supporting frame member with means thereon forming guide tracks, switch actuators mounted for movement and being guided by said guide tracks between switch actuating and nonactuating positions, switch means mounted on said supporting frame and disposed in the path of said actuators for operation by the same, reciprocable plunger members connected with said actuators and operable to move said actuators to switch actuating position, inserts forming guides for said plunger members mounted on said supporting frame member in spaced relation to said switch actuators, resilient means urging said switch actuators toward a non-actuating position, and means for releasably latching each plunger when it is moved to switch actuating position, and a plurality of lockout members slidably mounted end-to-end on said frame member for movement in a path normal to the path of movement of said plunger members, said lockout members having portions engageable by said plunger members so as to block switch actuating movement of said plunger members and cam surfaces on other portions engageable by said plunger members so as to cam said lockout members to a position for blocking switch actuating movement of an adjoining plunger member, and certain of said lockout members being of a length sufiicient to block switch actuating movement of a plurality of said plunger members.

References Cited UNITED STATES PATENTS 955,134 4/1910 Cadell. 1,105,629 8/1914 Dixon. 3,281,544 10/1966 Bailey et al.

FOREIGN PATENTS 331,619 8/1930 Great Britain.

ROBERT K. SCHAEFER, Primary Examiner M. GINSBURG, Assistant Examiner UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,487 ,178 December 30 1969 Glenn M. Stout It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2 line 64 "eements" should read elements line 71, "actuaing" should read actuating Column 3, line 48 "late" should read plate Column 5 line 19 after "other" insert end to one of the bolts 25 so as to normally Column 6 line 47 "operaable" should read hold the operable line 69 after "to" insert a Signed and sealed this 30th day of June 1970 (SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer 

